# Applications: Other

##### Eisenstein's Criterion

Eisenstein's criterion provides a useful way to figure out the Galois group of a polynomial. If one knows the factors of a polynomial f, then using the Galois groups of those factors, one can determine the Galois group of f, as the Galois group of f also contains all the Galois groups of its factors.

##### Quaternion Group

Galois groups have also been found to have applications within the realm of quaternion group theory.

Figure 6.1

Interestingly, the Galois group of the splitting field of the polynomial that appears in figure 6.1 over the rationals is the same as the quaternion group. A section on this type of groups is provided in further reading, and if one is not familiar with quaternions, another article on this website describes the fundamentals.

##### In Other Fields Outside Mathematics

Galois theory is rarely applicable outside of mathematics. Therefore it is often difficult to find applications of Galois groups outside of the realm of graduate level mathematics. Galois theory and Galois groups have provided a nice way to solve problems within the realm of mathematics, but like some concepts within modern pure math, it just has not found many direct applications in other fields yet.

##### Associations with other concepts

Obviously Galois groups is associated with Galois theory. The fundamental theorem of Galois was explored in this article. In addition, group theory and fields are another major topic associated with the Galois and investigated in this article, so if one desires to learn more about group theory, an article on it is provided in the references and further reading. Moreover, other treatments of Galois theory and groups are provided in the further reading section, in case one wants to learn it from a different perspective. However, some of these articles may be more rigorous and demand a certain level of mathematical maturity or knowledge level in order to comprehend them appropriately.

Furthermore, if the kind of content in this article is especially interesting to somebody, he/she should seek out Abstract Algebra textbooks or perhaps take a course on the subject.

## Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett